But Linda Chaves, a senior seafood industry adviser in the National Marine Fisheries Service said it was premature to say that Alaska definitely will have the power to prevent the farms.

Chaves said it depends on the final wording of legislation the Commerce Department expects to roll out in coming weeks setting up a "regulatory framework" for aquaculture development in the federal waters, which extend from three to 200 miles offshore.

"I don't know what's going to be in the legislation at the end of the day," Chaves said.

Under Alaska law, fish farming is banned in state waters, which extend from the beach to three miles out.

Many Alaska commercial fishermen and politicians including Gov. Frank Murkowski, oppose placing fish farms in the more remote federal waters. Fish farming is legal there now, but federal officials say it's unlikely to develop without a law to smooth out how operators can obtain permits.

Alaska has the most coastline and the biggest commercial fisheries of any state. Murkowski has called for a five-year ban on new aquaculture sites in federal waters pending studies of possible harm to the environment and the state's wild fish.

At a public meeting Tuesday at the Hilton Anchorage, federal and state officials outlined the global growth of fish and shellfish aquaculture, and how the U.S. government hopes to regulate development of ocean aquaculture.

About 30 people attended. Nearly all who spoke oppose fish farming in Alaska. Some said farmed fish could escape from cages and displace wild fish in spawning streams. Others said aquaculture could sink the economics of traditional commercial fishing.

William Evans, a Copper River commercial salmon fisherman who came to the meeting wearing his rubber deck boots, summed up general sentiment in the room.

"I'm not particularly against fish farms," he said, "except in the state of Alaska."

Chaves and other officials said aquaculture has great potential, if not in Alaska, then in other states. Domestic seafood demand outstrips the supply from U.S. fishermen, and the difference comes from imports, she said.

Gunnar Knapp, a University of Alaska Anchorage economist and an authority on world salmon markets, said aquaculture is underpinning a healthy-diet protein revolution that could someday match the huge growth in chicken consumption since the late 1930s.

Alaska fishermen are going to feel heavy competition from farmers elsewhere, Knapp said. Already, salmon fishermen have seen the value of their catches plunge.

Alaska might not be the best state for ocean fish farming, Knapp said. The state lacks roads, labor costs are high and Alaska is far from markets, he said.

Chaves said federal officials would not permit fish farms in waters off Alaska if the state opposed them under the Coastal Zone Management Act, which coordinates federal and state objectives on coastal and ocean development.